1. Field of the Invention
This invention relates to air filters and more particularly to a filter assembly for use in air conditioning systems which utilizes an air permeable filter media in a pleated form.
2. Description of the Related Art
In air conditioning systems, the air filters employed must be capable of filtering out fine particles of foreign matter such as dirt particles and dust to avoid their entry into the air conditioned space. Filters capable of filtering out fine particles offer considerable resistance to the flow of air. One way of alleviating this problem is to provide a large area filtering surface by successively bending a flat filtering media back and forth on itself to form a pleated or undulated configuration. While providing the desired filtering area so as to permit adequate air flow, this pleated configuration is incapable of self support. To provide such support a wire grid may be attached to the pleated filter media, such as described in U.S. Pat. No. 4,177,050 issued Dec. 4, 1979 to Robert M. Culbert and Robert R. Raber, Jr., inventor of the present invention. The use of metal in the filter assembly makes the unit difficult to discard by incineration, which is the manner such units are generally disposed of when discarded. Metal remaining in the incinerated debris could constitute an environmental hazard which the Environmental Protection Agency could require removal of, at great expense to the user.
In the system described in the aforementioned '050 patent, additional support for the pleated filter element is provided in the form of spine or web structures from which a plurality of finger portions extend into the pleats. This unitary structure for providing support for the pleats has the disadvantage of adding additional weight to the unit. Further, if any one of the fingers should be bent or otherwise damaged, it is necessary to replace the entire structure. Also, the unitary structure employed is more costly than the unitary finger elements employed in the present invention.